The ship carrying the 22-foot-wide ship-to-shore (STS) cranes arrived at the Port of Boston on June 22, 2021, and headed for the terminal’s brand new, 50-foot-deep Berth 10. Awaiting the specially rigged ship were crews provided by South Boston-based Daniel Marr & Son Company, who carefully offloaded the three gantry cranes that had been manufactured for Massport by Shanghai Zhenhua Heavy Industries Co., Ltd. (ZPMC). The cranes had been held in an upright position for the entire journey by special sea-fastening safeguards.
In addition to moving these giant cranes from the delivery vessel, Marr will be assisting during commissioning of the cranes, a procedure that includes a number of tests, a series of inspections, and training personnel before regular crane operations can begin.
“The most interesting challenge of this job was getting the cranes off the ship,” said Richard “Rich” Burns, President of Daniel Marr & Son Company. The ship was modified to carry the gantry cranes with special sea-fastening rigging that included large steel pipe braces positioned at a 45 degree angle to the horizontal cargo beam. The bottom end of the braces were welded to the ship deck and the top end welded to the horizontal cargo beam of each crane. Furthermore, there were heavy steel cables connecting the top of each crane to the deck. This sea fastening system thoroughly braces the cranes and helps control yaw in rough seas.
“They (ZPMC) are familiar with us. We have the equipment and the ironworker crews. We supplied the labor and equipment for offloading the three cranes. And we will still be working with them throughout the commissioning process. The key field personnel on the project have been Ironworker General Foreman Jenner Helstrom, and Field Operations Manager John Seward for Daniel Marr & Son.”
Your local Gomaco dealer |
---|
Gomaco -Contact Local |
Burns described the procedure that was developed to safely move a 20-story mega-ton gantry crane off the ship:
They attached a railroad-like steel bogie – a modular framework of four steel railroad wheels and axles – to each leg of a crane. Meanwhile landside crews assembled a temporary railroad of big steel girders and rails. Then they waited for the tide – the Port of Boston has a mean tidal range of 9.5 feet. When the crane bogie wheels on the ship lined up with the temporary railroad tracks on the berth pavement, they used winches and counterweights to pull the gantry crane off the ship and onto the temporary berth tracks.
The first phase of the project, which involved the dredging of the inner harbor, was completed in December 2017. Phase II was completed in November 2020, deepening the harbor to -47 feet and expanding the length of the turning basin to 1,725 feet. And the deepening of the main ship channels began in July 2018 to better accommodate present-day container vessels, as well as even bigger capacity ships.
Massport’s latest gantry cranes are capable of servicing container ships holding 12,000- to 14,000 TEUs (twenty-foot equivalent container units). For comparison, the existing Conley Terminal usually handles ships carrying 5,000 TEUs, and can service up to 10,000 TEUs in special circumstances.
TEU containers used in the U.S. typically measure about 8 feet tall by a little less than 8 feet wide, with lengths of 20 feet and 40 feet. The new gantry cranes can reach across a row of 22 containers on a ship to pluck a single container and place it on a waiting landside chassis. A chassis is a wheeled metal frame that is hauled over roads by a semi-tractor.
Your local Trimble Construction Division dealer |
---|
SITECH Northeast |
SITECH Allegheny |
Fifth generation Daniel “Dan” Marr is the Chief Executive Officer (CEO) of the Marr Companies. He is responsible for directing the day-to-day operations of the company, and formulating plans and policies to achieve company objectives. He joined Marr in 1973.